Solvothermal Growth of Chiral β-In₂S₃ Nanosheet Arrays for Circularly Polarized Photodetection

Abstract

The circularly polarized state of light can carry encoding information through polarization modulation and structural information from the emitter or propagation medium. Therefore, the detection of the polarization state of light is a central function in various applications. One of the concise strategies is to transform left- and right-handed circularly polarized light (CPL) directly into distinguishable electronic signals using chiral structured materials. In this study, chiral films of β-In2S3 vertical nanosheet arrays are successfully grown using a facile solvothermal route. Chirality originates from the distortion of nanosheets with left or right-handedness controlled by the introduction of l-/d-cysteine as chiral inducers. Circularly polarized photodetectors based on chiral β-In2S3 films are fabricated. They exhibit good performances with a responsivity (R) of 8.0 A/W, photodetectivity (D*) of 5.0 × 1012 Jones, the photocurrent dissymmetry factor (g Iph) of 0.34, and external quantum efficiency (EQE) of 2.2 × 103 (%) for a CPL of 450 nm.